## Copyright (C) 2007   Sylvain Pelissier   <sylvain.pelissier@gmail.com>
##
## This program is free software; you can redistribute it and/or modify
## it under the terms of the GNU General Public License as published by
## the Free Software Foundation; either version 2 of the License, or
## (at your option) any later version.
##
## This program is distributed in the hope that it will be useful,
## but WITHOUT ANY WARRANTY; without even the implied warranty of
## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
## GNU General Public License for more details.
##
## You should have received a copy of the GNU General Public License
## along with this program; If not, see <http://www.gnu.org/licenses/>.

## -*- texinfo -*-
## @deftypefn {Function File} {[@var{w}] =} bohmanwin(@var{L})
##	Compute the Bohman window of lenght L.
## @seealso{rectwin,  bartlett}
## @end deftypefn

function [w] = bohmanwin(L)
	if (nargin < 1); usage('bohmanwin(x)'); end
	if(! isscalar(L))
		error("L must be a number");
	endif
	
	if(L < 0)
		error('L must be positive');
	end
	
	if(L ~= floor(L))
		L = round(L);
		warning('L rounded to the nearest integer.');
	end
	
	if(L == 0)
		w = [];
	
	elseif(L == 1)
		w = 1;
		
	else
		N = L-1;
		n = -N/2:N/2;
	
		w = (1-2.*abs(n)./N).*cos(2.*pi.*abs(n)./N) + (1./pi).*sin(2.*pi.*abs(n)./N);
		w(1) = 0;
		w(length(w))=0;
		w = w';
	end
endfunction;